Chief Superintendent Nick Aldworth, national co-ordinator for the police ‘protect and prepare’ strategy, said: "As people are enjoying the festive season, they will see a visible security presence with police patrols and additional security in crowded places.

"Unpredictable deployments across the UK will also provide an additional layer of protection, with specially-trained uniformed and plain clothes officers working to deter, detect and disrupt hostile reconnaissance and encourage the public and businesses to be their extra eyes and ears and report anything that doesn't feel right."